Polyethylene backboard training device

ABSTRACT

A backboard training device having high density polyethylene panels mounted so that buckling is avoided and unwanted sound is reduced.

This application claims priority to U.S. patent app'n Ser. No. 60/990,974, filed 29 Nov. 2007, and Ser. No. 12/022,295, filed 30 Jan. 2008, the complete disclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a backboard training device having high density polyethylene panels mounted so that buckling is avoided and unwanted sound is reduced.

BACKGROUND OF THE INVENTION

A variety of sports utilize backboard training for practice and conditioning. Tennis players develop stroke technique, footwork and stamina. Soccer, Lacrosse, and basketball players likewise utilize the rebound of backboards to develop skills specific to their sports. The innate simplicity of a backboard belies its ability to provide both introductory through advanced level skill development in numerous sports.

Backboard practice can take place against a garage door or any flat wall. Plywood and concrete block is often used to fashion backboards. However, both such products require constant maintenance. Wood requires painting, sealing and flashing to prevent rot and warping. Block is expensive to build and needs painting, caulking, parging and pointing.

Backboard training is so popular that a number of companies have introduced panelized backboard products to the market place. These products are generally sold in custom paneled increments of 4 feet wide by 8 feet or 10 feet in height. The panels are normally attached to an existing fence structure or other support poles. The more panels you buy, the wider your backboard can be.

Backboard kits are available with plywood panels, MDO panels, fiberglass panels, vacuum molded or otherwise molded plastic panels or painted-treated drywall panels.

All of the above systems have limitations and problems.

Fiberglass, vacuum molded and injection molded panels are subject to damage when used for Lacrosse or Soccer Practice. The balls used in these sports can puncture or crack the panels ruining the product. Fiberglass backboards utilize a thin, painted-on surface that is subject to U.V degradation and often develops dead spots.

Plywood and MDO Board panels are subject to rotting, warping, delamination and require constant painting, sealing and flashing.

HDPE panels are very difficult to mark, for example with lines, because paint and adhesives to do not stick to the surface.

SUMMARY OF THE INVENTION

An objective of the invention is to provide a backboard training device that is low maintenance, such that it is not prone to rotting, warping, or delamination and does not require constant painting, sealing and flashing.

Another objective of the invention is to solve the problem of buckling associated with HDPE panels.

A further objective of the invention is to solve the problem of undesirable sound associated with use of HDPE panels.

Another objective of the invention is to solve the problems associated with marking HDPE panels.

The above objectives and other objectives are obtained by a backboard training device comprising:

-   -   a. at least two panels mounted to a rigid support by a movable         mount, the panels comprising high density polyethylene having a         high coefficient of expansion;     -   b. the movable mount constructed and arranged to allow the         panels to move in relation to each during ambient temperature         changes to avoid buckling of the panels;     -   c. an anti-vibration strip disposed between the movable mount         and the panels; and     -   d. an anti-friction strip disposed between the movable mount and         the panels to allow the panels to move in relation to one         another.

In a preferred embodiment, the movable mount comprises a plurality of wheels attached to the panels, and at least one track mounted to the rigid support, the wheels contacting the at least one track so that the panels can slide in relation to one another in a horizontal direction.

In another preferred embodiment, the movable mount comprises a plurality of slots substantially aligned in a horizontal direction, the panels being movably secured to the movable mount using bolts that pass through the panels and the slots, the slots having a width greater than the diameter of the bolts to allow movement in a vertical direction and the slots having a length to accommodate expansion and contraction of the panels.

The objectives associated with marking and other objectives are obtained by an HDPE panel comprising a surface layer and at least one other layer bonded to the surface layer, the surface layer and the at least one other layer having different colors, and at least one marking formed by removing the surface layer in the shape of the marking to expose the color of the at least one other layer.

The above objectives are also obtained by a backboard training device comprising a plurality of HDPE panels, each HDPE panel comprising a surface layer and at least one other layer bonded to the surface layer, the surface layer and the at least one other layer having different colors, and at least one marking formed by removing the surface layer in the shape of the marking to expose the color of the at least one other layer, wherein the other layer and surface layer are coextruded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a top view of buckled HDPE panels which are mounted to rigid support posts using a non-movable mount;

FIG. 2 illustrates a front view of HDPE panels mounted to rigid support posts using a non-movable mount;

FIG. 3. illustrates a non-movable mount;

FIG. 4. illustrates a movable mount having slots;

FIG. 5 illustrates a side view of HDPE panels mounted to a movable mount having slots;

FIG. 6 illustrates a side view of a movable mount having wheels;

FIG. 7 illustrates a front view of HDPE panels mounted to a movable mount having wheels;

FIG. 8 illustrates a side view of a movable mount having wheels;

FIG. 9 illustrates a side view of a movable mount having wheels;

FIG. 10 illustrates a front view of HDPE panels mounted to a movable mount having wheels;

FIG. 11 illustrates a frontal view of an HDPE panel;

FIG. 12 illustrates a side view of an HDPE panel; and

FIG. 13 illustrates a backboard training device comprising a plurality of HDPE panels.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be explained with reference to the attached Figs., without being limited thereto. The backboard training device comprises at least two HDPE panels mounted to a rigid support by a movable mount. The HDPE panels are highly flexible, resist puncture, cracking and weathering. However, the HDPE panels have a high coefficient of expansion, which results in severe buckling of the panels if they are not movably mounted to the rigid support. The HDPE panels have a high coefficient of expansion, for example greater than 0.00005 in/in ° F. The HDPE panels are usually about 4 feet by 8 feet or 4 feet by 10 feet, but can be sized as desired. The panels are usually at least about 0.5 inches in thickness to provide sufficient rigidity to avoid deforming during use, but can be any thickness as desired. Usually, the multiple panels are aligned in a horizontal direction with the length facing upward, as shown in the accompanying Figs. The movable mount is constructed and arranged to allow the panels to move in relation to each other during ambient temperature changes to avoid buckling of the panels.

The movable mount disclosed herein allows the HDPE panels to expand and contract with ambient temperature variations without developing undesirable warping or buckling that will render the backboard unplayable, damage the hardware of the mounting system, and damage the panels.

When an HDPE panel is bolted directly to a solid support without a means for it to freely expand and contract, the panels will buckle. As shown in FIGS. 1-3, the panels 2 are mounted to the rigid support posts 4 using a non-movable mount 6 and bolts 8, such that the panels 2 cannot move in relation to one another. When the HDPE panels expand due to increased ambient temperature, they buckle as shown in FIG. 1, rendering them unplayable. Furthermore, the buckling can sheer off the mounting bolts 8.

Friction-Reducing, Vibration-Dampening Strip

A friction-reducing, vibration dampening strip 16 is disposed between the movable mount and the panels. The friction-reducing, vibration dampening strip 16 serves two important purposes unique to the present invention:

-   -   a. It allows the panels to expand and contract smoothly along         the face of the mounting bracket; and     -   b. It reduces undesirable noise-causing vibration between the         HDPE backboard panel and the steel mounting components during         use.

The noise associated with backboard practice has long been considered a nuisance.

I have found that if the HDPE panels are bolted directly to the support posts, a very loud undesirable sound is produced by the impact of balls on the HDPE panels. For example, through the use of the strip 16, I have been able to reduce the sound of a tennis ball hitting the backboard to a decibel level less than a tennis ball hitting a tennis racket, making the backboard far more attractive to potential customers.

Furthermore, I have also found that the movement of the panels 2 during contraction and expansion can be made uniform by using the strip 16. The strip 16 can comprise open or closed cell foam, polystyrene, felt, rubber or synthetic material so long as it is weather proof. The surface of the strip 16 constructed to face the HDPE panels 2 should be formed of a low friction material, such as closed cell polystyrene. If desired, the strip 16 can be in multiple layers or separate strips that are placed upon one another, so long as the anti-friction surface faces the HDPE panels 2.

Slotted Movable Mount

It has been found that the use of a movable mount 12, as shown in FIGS. 4 and 5, having elongated slots 14 allows the HDPE panels 2 to expand and contract in a horizontal direction along the movable mount 12. The movable mount 12 directly replaces the non-movable mount 6 shown in FIG. 2. The HDPE panel 2 is bolted directly to the movable bracket 12 using bolts 8 and nuts 9, utilizing minimal torque on the mounting bolts. Preferably, the bolts 8 and nuts 9 are corrosion resistant. Preferably, the head of the bolt 8 is recessed in the HDPE panel 2, as shown in FIG. 5. The bolts 8 and slot 14 are sized such that the diameter of the bolt 8 is smaller than the width of the slot 14 so that the bolt 8 can slide in the slot 14. A friction-reducing and vibration-dampening strip 16 is placed between the panel 2 and a surface of the movable mount 12. The HDPE panel 2 can expand and contract horizontally by the bolts 8 sliding in the slot 14 and the panel 2 sliding along the friction-reducing and vibration dampening strip 16.

The movable mount 12 is secured to the support posts 4 using clamps or other securing structure as desired.

The length of the slot 14 should be sufficient to account for the total horizontal expansion and contraction of all the HDPE panels 2 added together.

The width of the slot 14 can also be made sufficiently greater than the diameter of the bolt 8 to account for vertical expansion of one panel. The vertical expansion will typically be less than the horizontal expansion since usually one panel is used in the vertical direction and multiple panels are used in the horizontal direction.

Upward Facing Track and Wheel Movable Mount

It has been found that the use of a movable mount 20, as shown in FIGS. 6 and 7, having a track 21 and wheels 22 allows the HDPE panels 2 to expand and contract in a horizontal direction along the movable mount 20. The rotating wheels 22 are attached to the HDPE panels 2 using bolts 8 and nuts 9. The wheels 22 are then introduced to the track 21. Preferably, the track 21 is in the form of an upward-facing “U” shaped channel, as shown in FIG. 6. Once the wheels 22 are positioned on the track 21, the nuts 9 are tightened on the backside of the wheels 22. A friction-reducing and vibration dampening strip 16 is present between the movable mount 20 and the HDPE panels 2. The nuts 9 should only be tightened sufficiently to hold the HDPE panels 2 against the strip 16 but not so tight that the HDPE panels 2 cannot move in a horizontal direction due to contraction and expansion. This provides a clamping force that secures the HDPE panels 2 to the movable mount 20.

The HDPE panels 2 can also be secured to the movable mount 20 using optional anti-lift clamps 23 as shown in FIG. 9. The anti-lift clamps 23 are secured to the wheels 22 using the bolt 8 and nut 9. A part of the anti-lift clamp 23 travels below the track 21, preventing the wheel 22 from lifting off of the track 21.

The movable mount 20 is secured to the support posts 4 using a clamp 24 or other securing structure as desired.

If desired, the track be angled away from the HDPE panels 2 so that as the HDPE panels 22 expand in the vertical direction the wheels 22 can ride higher on the angled track on the upper tracks compared to the wheels 22 on the bottom most track.

Forward-Facing Track and Wheel Movable Mount

It has been found that the use of a movable mount 30, as shown in FIGS. 9 and 10, having a track 32 and wheels 34 allows the HDPE panels 2 to expand and contract in a horizontal direction along the movable mount 30.

The rotating wheels 34 are attached to the HDPE panels using bolts 8 and nuts 9. The wheels 34 and HDPE panels 2 are then introduced to the track 32. Preferably, the track 32 is in the form of a forward-facing “U” shaped channel as shown in FIG. 8.

Friction-reducing and vibration dampening strips 16 are present between the movable mount 30 and the HDPE panels 2. The nuts 9 should only be tightened sufficiently to hold the HDPE panels 2 against the strips 16 but not so tight that the HDPE panels 2 cannot move in a horizontal direction due to contraction and expansion.

The movable mount 30 can be secured to the support posts 4 using curved clamps 38, bolts 36 and nuts 40.

Example of HDPE Panels

A non-limiting example of a HDPE panel has a width of about 4 feet, a height of about 8 or 10 feet, and a thickness of about ¾ inch. The HDPE panel has a coefficient of expansion of about 0.000067 in/in ° F.

Preferred Thermal Expansion &Contraction Coefficiants for: 48″ Wide HDPE Backboard Panels Note: Provides maximum strength and durability in all tested U.S. Climates when mounted in accordance with the enclosed, specified mounting systems. Thermal expansion or contraction coefficient 0.000067 in/in F. Sheet Length (inches) and contraction/expansion (inches) All for 48″ wide panelled increments Temperature Differential (F.) 96 120 144 5 0.0322 0.0402 0.0482 10 0.0643 0.0804 0.0965 15 0.0965 0.1206 0.1447 20 0.1286 0.1608 0.1930 25 0.1608 0.2010 0.2412 30 0.1930 0.2412 0.2894 35 0.2251 0.2814 0.3377 40 0.2573 0.3216 0.3859 45 0.2894 0.3618 0.4342 50 0.3216 0.4020 0.4824 55 0.3538 0.4422 0.5306 60 0.3859 0.4824 0.5789 65 0.4181 0.5226 0.6271 70 0.4502 0.5628 0.6754 75 0.4824 0.6030 0.7236 80 0.5146 0.6432 0.7718 85 0.5467 0.6834 0.8201 90 0.5789 0.7236 0.8683 95 0.6110 0.7638 0.9166 100 0.6432 0.8040 0.9648 105 0.6754 0.8442 1.0130 110 0.7075 0.8844 1.0613 115 0.7397 0.9246 1.1095 120 0.7718 0.9648 1.1578 125 0.8040 1.0050 1.2060

Another example of a suitable HDPE panel is disclosed in my U.S. patent application Ser. No. 12/022,295. FIG. 11 shows a front view of an exemplary HDPE panel 42 having a surface layer 43 in one color and an other layer 38 having a second color. The HDPE panel 32 has marking 36 in the shape of a line engraved in the surface 44 so the second color of the other layer 8 is exposed. FIG. 12 is a side view of the HDPE panel 42 having a surface 44 in one color and a marking 46 in the shape of a line engraved in the surface layer 44 so the second color of the other layer 48 is exposed. FIG. 12 also shows an optional third layer 50.

The thickness of the surface layer 44 can be as desired. The surface layer 44 should be sufficiently thick so that any wear marks from use do not show the color of the other layer 48. Preferably the thickness of the surface layer 44 is about ¼ inch or less, most preferably about ⅛ inch or less.

The HDPE panels are typically sized at about 4 feet by 8 feet or 4 feet by 10 feet. However, any desired size can be produced. The thickness of the HDPE panels should be selected to provide a desired level of rigidity during use. Typically, a thickness from about 0.5 inch to about 2 inches, preferably about 0.7 to about 1.5 inches, is sufficient. If the panels are too thick, then weight and higher cost may become a problem. If the panels are too thin, they may undesirably flex during use.

The HDPE panels can withstand the impact of lacrosse balls, soccer balls, baseballs and soccer balls without being punctured, split or otherwise damaged. The HDPE panels are highly immune to degradation or damage due to drastic temperature variations, weather or air pollution conditions.

The HDPE materials are now well known. Thus, the HDPE material can be selected as desired. Formation of panels using extrusion methods are also now well known. Those skilled in the art will easily be able to use known manufacturing methods to form the novel HDPE panels described herein. While the different layers of the HDPE panels can be bonded using any desired method, preferably the layers are coextruded.

Coloration of HDPE materials by addition of pigments is also well known. Using the description provided herein, one skilled in the art will be able to use known methods to coextrude the novel HDPE panels having different colored layers.

Preferably, the HDPE material includes ultra-violet inhibitors to reduce damage caused by sunlight.

The markings 46 can be in any shape as desired. Non-limiting examples a markings 46 are tennis net lines and target markings, such as a Lacrosse Goal or Soccer Goal, engraved into the panel, thus, providing a permanent, no-maintenance feature.

The HDPE panels can be used in a backboard training device by mounting a plurality of them to a rigid support. Preferably, a movable mount is utilized to avoid buckling due to expansion and contraction. An example of a backboard training 52 device utilizing multiple HDPE panels 42 is shown in FIG. 3, having the markings 46 lined up to form a tennis net line.

If the panels are to be used as a tennis training backboard, preferably, the surface layer 44 is colored green and the other layer 48 is colored white, so that white lines representing the net and/or out of bounds are clearly defined.

While the claimed invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made to the claimed invention without departing from the spirit and scope thereof. 

1. A backboard training device comprising: at least two panels mounted to a rigid support by a movable mount, the panels comprising high density polyethylene having a high coefficient of expansion; the movable mount constructed and arranged to allow the panels to move in relation to each during ambient temperature changes to avoid buckling of the panels; an anti-vibration strip disposed between the movable mount and the panels; and an anti-friction strip disposed between the movable mount and the panels to allow the panels to move in relation to one another.
 2. A backboard training device according to claim 1, wherein the anti-vibration strip and the anti-friction strip are combined.
 3. A backboard training device according to claim 1, wherein the movable mount comprises a plurality of wheels attached to the panels, and at least one track mounted to the rigid support, the wheels contacting the at least one track so that the panels can slide in relation to one another in a horizontal direction.
 4. A backboard training device according to claim 3, wherein the track comprises a U-shaped channel having an opening facing in an upward direction.
 5. A backboard training device according to claim 3, wherein the track comprises a U-shaped channel having an opening facing the panels.
 6. A backboard training device according to claim 1, wherein the movable mount comprises a plurality of slots substantially aligned in a horizontal direction, the panels being movably secured to the movable mount using bolts that pass through the panels and the slots, the slots having a width greater than the diameter of the bolts to allow movement in a vertical direction and the slots having a length to accommodate expansion and contraction of the panels.
 7. A backboard training device according to claim 1, wherein the panels comprise HDPE panels having a surface layer and at least one other layer bonded to the surface layer, the surface layer and the at least one other layer having different colors, and at least one marking formed by removing the surface layer in the shape of the marking to expose the color of the at least one other layer.
 8. A backboard training device according to claim 7, wherein the surface layer is green, the other layer is white, and the marking comprises at least one line.
 9. A backboard training device according to claim 7, wherein the surface layer and other layer are formed by coextrusion.
 10. A backboard training device according to claim 7, wherein the panel is about 4 feet by 8 feet.
 11. A backboard training device according to claim 7, wherein the panel is about 4 feet by 10 feet.
 12. A backboard training device according to claim 7, wherein the thickness of the panel is about 0.5 inch to about 2 inches.
 13. A backboard training device according to claim 7, wherein the marking is a net line, the color of the surface layer is green, and the color of the other layer is white.
 14. A backboard training device according to claim 7, wherein the HDPE panels being mounted so that the markings one each panel line up to form a tennis line. 